diff --git a/scripts/gui/microbe_editor.mjs b/scripts/gui/microbe_editor.mjs
index cf08ff04127..408bc803cfc 100644
--- a/scripts/gui/microbe_editor.mjs
+++ b/scripts/gui/microbe_editor.mjs
@@ -63,6 +63,10 @@ const organelleSelectionElements = [
     {
         element: document.getElementById("addChromatophor"),
         organelle: "chromatophors"
+    },
+    {
+        element: document.getElementById("addNucleus"),
+        organelle: "nucleus"
     }
 
     // AddPilus
@@ -126,7 +130,9 @@ export function setupMicrobeEditor(){
 
         element.element.addEventListener("click", (event) => {
             event.stopPropagation();
-            onSelectNewOrganelle(element.organelle);
+            if(!element.element.classList.contains("DisabledButton")) {
+                onSelectNewOrganelle(element.organelle);
+            }
         }, true);
     }
 
@@ -193,6 +199,11 @@ export function setupMicrobeEditor(){
         // Event for restoring the microbe GUI
         Leviathan.OnGeneric("MicrobeEditorExited", doExitMicrobeEditor);
 
+        // Event for update buttons depending on presence or not of nucleus
+        Leviathan.OnGeneric("MicrobeEditorNucleusIsPresent", (event, vars) => {
+            updateGuiButtons(vars.nucleus);
+        });
+
     } else {
         updateSelectedOrganelle("cytoplasm");
     }
@@ -287,6 +298,33 @@ function updateGeneration(generation){
     generation;
 }
 
+//! Updates buttons status depending on presence of nucleus in GUI
+function updateGuiButtons(isNucleusPresent){
+
+    if(!isNucleusPresent &&
+        !document.getElementById("addMitochondrion").classList.contains("DisabledButton")) {
+
+        document.getElementById("addNucleus").classList.remove("DisabledButton");
+        document.getElementById("addMitochondrion").classList.add("DisabledButton");
+        document.getElementById("addChloroplast").classList.add("DisabledButton");
+        document.getElementById("addChemoplast").classList.add("DisabledButton");
+        document.getElementById("addNitrogenFixingPlastid").classList.add("DisabledButton");
+        document.getElementById("addVacuole").classList.add("DisabledButton");
+        document.getElementById("addToxinVacuole").classList.add("DisabledButton");
+
+    } else if(isNucleusPresent &&
+        document.getElementById("addMitochondrion").classList.contains("DisabledButton")) {
+
+        document.getElementById("addNucleus").classList.add("DisabledButton");
+        document.getElementById("addMitochondrion").classList.remove("DisabledButton");
+        document.getElementById("addChloroplast").classList.remove("DisabledButton");
+        document.getElementById("addChemoplast").classList.remove("DisabledButton");
+        document.getElementById("addNitrogenFixingPlastid").classList.remove("DisabledButton");
+        document.getElementById("addVacuole").classList.remove("DisabledButton");
+        document.getElementById("addToxinVacuole").classList.remove("DisabledButton");
+    }
+}
+
 //! Updates generation points in GUI
 function updateSpeed(speed){
     document.getElementById("speedLabel").textContent =
diff --git a/scripts/gui/thrive_gui.html b/scripts/gui/thrive_gui.html
index c46a84ad208..0bea23fd77e 100644
--- a/scripts/gui/thrive_gui.html
+++ b/scripts/gui/thrive_gui.html
@@ -398,7 +398,7 @@
                 A space or vesicle within the cytoplasm of a cell, enclosed by a membrane and used to hold compounds</span>
                 <div id="VacuoleIcon"></div>Vacuole<br>30 MP</td>
 	          <td id="addToxinVacuole" class="OrganelleListItem">
-              <span class="tooltiptext">
+                <span class="tooltiptext">
                 Toxin Vacuole <hr><br> Cost: 80 mutation points<hr><br> 
                 Performs Process: OxytoxyNT Production<br>(1 Oxygen + 5 ATP -> 5 Oxytoxy)/Second (Depending On Environmental Oxygen)<hr><br>
                 Allows for production and storage of OxytoxyNT which can be shot at enemy cells using E. The more of this organelle you have the faster your toxin fire rate aswell.
@@ -412,10 +412,18 @@
                 Chemoplast<hr><br> Cost: 40 mutation points<hr><br> 
                 Performs Process: Chemosynthesis<br>(0.09 CO2 + 1 Hydrogen Sulfide -> 2 Glucose)/Second (Depending On Environmental C02)<hr><br>
                 Allows for synthesis of glucose from hydrogen sulfide and atmospheric carbon dioxide.
-               <br>
-               Can be used to process the normally toxic soup containing hydrogen sulfide that comes out of hydrothermal vents at the bottom of the ocean. Into glucose.
-               </span>
+                <br>
+                Can be used to process the normally toxic soup containing hydrogen sulfide that comes out of hydrothermal vents at the bottom of the ocean. Into glucose.
+                </span>
                 <div id="ChemoplastIcon"></div>Chemoplast<br>40 MP</td>
+            <td id="addNucleus" class="OrganelleListItem">
+                <span class="tooltiptext">
+                Nucleus<hr><br> Cost: 100 mutation points<hr><br>
+                Performs Process: Eukaryote Evolution<hr><br>
+                Allows for synthesis of RNA, MRNA, allows cell to evolve membrane bound organelles.
+                </span>
+                <div id="NucleusIcon">
+                </div>Nucleus <br>100 MP</td>
               <td id="addNitrogenFixingPlastid" class="OrganelleListItem">
                 <span class="tooltiptext">
                 Nitrogen Fixing Plastid<hr><br> Cost: 80 mutation points<hr><br> 
diff --git a/scripts/gui/thrive_style.css b/scripts/gui/thrive_style.css
index 05c14baa92b..be1a60e5c95 100644
--- a/scripts/gui/thrive_style.css
+++ b/scripts/gui/thrive_style.css
@@ -1105,6 +1105,15 @@ video {
   top: 15px;
 }
 
+#NucleusIcon {
+  position: relative;
+  left: calc(50% - 30px);
+  width: 60px;
+  height: 60px;
+  background-size: contain;
+  background-image: url("../../Textures/gui/bevel/NucleusIcon.png");
+}
+
 #CytoplasmIcon {
   position: relative;
   left: calc(50% - 30px);
diff --git a/scripts/microbe_stage/configs.as b/scripts/microbe_stage/configs.as
index a7ab339d2e5..ccf73f1a4cf 100644
--- a/scripts/microbe_stage/configs.as
+++ b/scripts/microbe_stage/configs.as
@@ -347,9 +347,7 @@ const dictionary STARTER_MICROBES = {
                 {"oxytoxy", InitialCompound(0)}
             },
             {
-                OrganelleTemplatePlaced("nucleus", 0, 0, 180),
-                OrganelleTemplatePlaced("cytoplasm", 1, 1, 0),
-                OrganelleTemplatePlaced("cytoplasm", -1, 2, 0)
+                OrganelleTemplatePlaced("cytoplasm", 0, 0, 0)
             },
             Float4(1, 1, 1, 1),
             false,
diff --git a/scripts/microbe_stage/microbe_editor/microbe_editor.as b/scripts/microbe_stage/microbe_editor/microbe_editor.as
index 27739eba152..79d4c320f65 100644
--- a/scripts/microbe_stage/microbe_editor/microbe_editor.as
+++ b/scripts/microbe_stage/microbe_editor/microbe_editor.as
@@ -51,6 +51,7 @@ class MicrobeEditor{
 
         placementFunctions = {
             {"nucleus", PlacementFunctionType(this.createNewMicrobe)},
+            {"nucleus", PlacementFunctionType(this.addOrganelle)},
             {"flagellum", PlacementFunctionType(this.addOrganelle)},
             {"cytoplasm", PlacementFunctionType(this.addOrganelle)},
             {"mitochondrion", PlacementFunctionType(this.addOrganelle)},
@@ -69,6 +70,7 @@ class MicrobeEditor{
     //! This is called each time the editor is entered so this needs to properly reset state
     void init()
     {
+        updateGuiButtonStatus(checkIsNucleusPresent());
         gridSceneNode = hudSystem.world.CreateEntity();
         auto node = hudSystem.world.Create_RenderNode(gridSceneNode);
         node.Scale = Float3(HEX_SIZE, 1, HEX_SIZE);
@@ -228,6 +230,12 @@ class MicrobeEditor{
 
     private void _addOrganelle(PlacedOrganelle@ organelle)
     {
+        // 1 - you put nucleus but you already have it
+        // 2 - you put organelle that need nucleus and you don't have it
+        if((organelle.organelle.name == "nucleus" && checkIsNucleusPresent()) ||
+            (organelle.organelle.prokaryoteChance == 0 && !checkIsNucleusPresent()) && organelle.organelle.chanceToCreate != 0 )
+                return;
+
         EditorAction@ action = EditorAction(organelle.organelle.mpCost,
             // redo
             function(EditorAction@ action, MicrobeEditor@ editor){
@@ -256,6 +264,9 @@ class MicrobeEditor{
                 LOG_INFO("Placing organelle '" + organelle.organelle.name + "' at: " +
                     organelle.q + ", " + organelle.r);
                 editor.editedMicrobe.insertLast(organelle);
+
+                // send to gui current status of cell
+                editor.updateGuiButtonStatus(editor.checkIsNucleusPresent());
             },
             // undo
             function(EditorAction@ action, MicrobeEditor@ editor){
@@ -274,6 +285,9 @@ class MicrobeEditor{
                     }
 
                 }
+
+                // send to gui current status of cell
+                editor.updateGuiButtonStatus(editor.checkIsNucleusPresent());
             });
 
         @action.data["organelle"] = organelle;
@@ -562,6 +576,25 @@ class MicrobeEditor{
         // LOG_WRITE("Mouse hex: " + qr + ", " + rr);
     }
 
+    bool checkIsNucleusPresent()
+    {
+        for(uint i = 0; i < editedMicrobe.length(); ++i){
+            auto organelle = cast<PlacedOrganelle>(editedMicrobe[i]);
+            if (organelle.organelle.name == "nucleus"){
+                return true;
+            }
+        }
+        return false;
+    }
+
+    void updateGuiButtonStatus(bool nucleusIsPresent){
+
+        GenericEvent@ event = GenericEvent("MicrobeEditorNucleusIsPresent");
+        NamedVars@ vars = event.GetNamedVars();
+
+        vars.AddValue(ScriptSafeVariableBlock("nucleus", nucleusIsPresent));
+        GetEngine().GetEventHandler().CallEvent(event);
+    }
 
     bool isValidPlacement(const string &in organelleType, int q, int r,
         int rotation)
diff --git a/scripts/microbe_stage/organelle_components/nucleus_organelle.as b/scripts/microbe_stage/organelle_components/nucleus_organelle.as
index c890b8a4643..1d01a48c64a 100644
--- a/scripts/microbe_stage/organelle_components/nucleus_organelle.as
+++ b/scripts/microbe_stage/organelle_components/nucleus_organelle.as
@@ -41,7 +41,7 @@ class NucleusOrganelle : OrganelleComponent{
         sceneNode1.Node.setPosition(Hex::axialToCartesian(q + 1, r + 1));
             //sceneNode1.Node.setOrientation(Ogre::Quaternion(Ogre::Radian(rotation),
                // Ogre::Vector3(0, .5, 1)));
-        sceneNode1.Node.setOrientation(Ogre::Quaternion(Ogre::Degree(rotation),
+        sceneNode1.Node.setOrientation(Ogre::Quaternion(Ogre::Degree(rotation+180),
                 Ogre::Vector3(0, 1, -1)));
         sceneNode1.Marked = true;
 
@@ -59,7 +59,7 @@ class NucleusOrganelle : OrganelleComponent{
         sceneNode2.Scale = Float3(HEX_SIZE, HEX_SIZE, HEX_SIZE);
         sceneNode2.Node.setPosition(Hex::axialToCartesian(q, r+.4));
 
-        sceneNode2.Node.setOrientation(Ogre::Quaternion(Ogre::Degree(rotation+10),
+        sceneNode2.Node.setOrientation(Ogre::Quaternion(Ogre::Degree(rotation+190),
                 Ogre::Vector3(0, 1, -1)));
         sceneNode2.Marked = true;
 
diff --git a/scripts/microbe_stage/organelle_table.as b/scripts/microbe_stage/organelle_table.as
index 6076900cf8f..0734a7ab1e7 100644
--- a/scripts/microbe_stage/organelle_table.as
+++ b/scripts/microbe_stage/organelle_table.as
@@ -256,7 +256,7 @@ void setupOrganelles(){
     nucleusParameters.mesh = "nucleus.mesh";
     nucleusParameters.chanceToCreate = 0; // Not randomly generated.
     nucleusParameters.prokaryoteChance = 0; // Not randomly generated.
-    nucleusParameters.mpCost = 0; //it's not supossed to be purchased.
+    nucleusParameters.mpCost = 100; //big evolution moment.
     nucleusParameters.initialComposition = {
         {"phosphates", 2},
         {"ammonia", 2}
diff --git a/scripts/microbe_stage/procedural_microbes.as b/scripts/microbe_stage/procedural_microbes.as
index 1a3116e559a..4ab982b99e8 100644
--- a/scripts/microbe_stage/procedural_microbes.as
+++ b/scripts/microbe_stage/procedural_microbes.as
@@ -191,10 +191,10 @@ array<PlacedOrganelle@>@ positionOrganelles(const string &in stringCode){
         const auto letter = CharacterToString(stringCode[i]);
         // LOG_WRITE(formatUInt(i) + ": " + letter);
         string name = string(organelleLetters[letter]);
-        //this places the nucleous
+        //this places the nucleus
         if(i == 0){
 
-            @pos = OrganelleTemplatePlaced(name, 0, 0, 180);
+            @pos = OrganelleTemplatePlaced(name, 0, 0, 360);
 
         } else {